Simulated physiological stretch increases expression of extracellular matrix proteins in human bladder smooth muscle cells via integrin α4/αv-FAK-ERK1/2 signaling pathway.

OBJECTIVES: To investigate the effect of simulated physiological stretch on the expression of extracellular matrix (ECM) proteins and the role of integrin α4/αv, focal adhesion kinase (FAK), extracellular regulated protein kinases 1/2 (ERK1/2) in the stretch-induced ECM protein expression of human bladder smooth muscle cells (HBSMCs). METHODS: HBSMCs were seeded onto silicone membrane and subjected to simulated physiological stretch at the range of 5, 10, and 15% elongation. Expression of primary ECM proteins in HBSMCs was analyzed by real-time polymerase chain reaction and Western blot. Specificity of the FAK and ERK1/2 was determined by Western blot with FAK inhibitor and ERK1/2 inhibitor (PD98059). Specificity of integrin α4 and integrin αv was determined with small interfering ribonucleic acid (siRNA) transfection. RESULTS: The expression of collagen I (Col1), collagen III (Col3), and fibronectin (Fn) was increased significantly under the simulated physiological stretch of 10 and 15%. Integrin α4 and αv, FAK, ERK1/2 were activated by 10% simulated physiological stretch compared with the static condition. Pretreatment of ERK1/2 inhibitor, FAK inhibitor, integrin α4 siRNA, or integrin αv siRNA reduced the stretch-induced expression of ECM proteins. And FAK inhibitor decreased the stretch-induced ERK1/2 activity and ECM protein expression. Integrin α4 siRNA or integrin αv siRNA inhibited the stretch-induced activity of FAK. CONCLUSION: Simulated physiological stretch increases the expression of ECM proteins in HBSMCs, and integrin α4/αv-FAK-ERK1/2 signaling pathway partly modulates the mechano-transducing process.

Non-functioning paraganglioma occurring in the urinary bladder: A case report and review of the literature.

Paraganglioma, also termed extra-adrenal pheochromocytoma, may be observed at the base of the skull and neck as well as within the mediastinum and periaortic region. The clinical symptoms of paraganglioma of the urinary bladder include intermittent hypertensive attacks, micturition, headaches and palpitations due to high catecholamine levels; these types of paragangliomas are extremely rare. However, certain bladder paragangliomas do not present with any of these symptoms; thus, surgeons are not pre-warned on how to prepare for their resection. Surgery to remove pheochromocytomas may therefore result in an intraoperative hypertensive crisis and increase the mortality rate. This infrequent type of paraganglioma is only recognized through histological examination following surgery. The current study reports the case of a 61-year-old male with urinary bladder paraganglioma. The patient presented with hypertension, which was controlled to within a normal range using diovan and norvasc treatment; in addition, the patient's blood pressure was not altered with urination or postural changes. The patient was not administered an α-blocking agent or a blood volume expander prior to the surgery, and during the partial cystectomy no hypertensive crisis occurred.

Simulated physiological stretch-induced proliferation of human bladder smooth muscle cells is regulated by MMPs.

Mechanical stimulation is an essential factor for organisms to develop normally. In bladder development matrix metalloproteinases (MMPs) play an important role through structure remodeling and regulating the cell proliferation. In this study, we investigated the simulated physiological stretch induced proliferation of HBSMCs; MMPs/TIMPs expression in stretch and non-stretch groups. HBSMCs were exposed to cyclic stretch with defined parameters (5%, 10% and 15% elongation). The expression of MMPs and TIMPs in each parameter and non-stretch groups was examined at the transcriptional and translational levels respectively. 5-Ethynyl-2'-deoxyuridine (EdU) assay was used to assess cell proliferation. In the presence of the broad spectrum MMPs inhibitor (Batimastat), cells proliferation, MMPs and tissue inhibitors of metalloproteinases (TIMPs) expression were assessed again. Compared with non-stretch group, HBSMCs in stretch groups showed higher proliferation. The expression of MMP-1, 2, 3, 7 was up-regulated in stretch groups, and it remained at the same high level in 10% and 15% stretch groups. TIMP-1, 2 expression only increased under 15% stretch. Stretch resulted in elevated cell proliferation was abolished by Batimastat. In conclusion, the proliferation of HBSMCs induced by stretch was resulted from the stretch-induced MMPs expression and release.

The role of mirabegron in overactive bladder: a systematic review and meta-analysis.

OBJECTIVE: To present a systematic review assessing the efficacy and safety of mirabegron for overactive bladder (OAB). MATERIALS AND METHODS: A literature search was performed using the Cochrane Library, MEDLINE, EMBASE and Science Citation Index Expanded. The literature reviewed included meta-analyses, randomized and nonrandomized prospective studies. We utilized mean difference (MD) to measure the mean number of incontinence episodes and the mean number of micturitions, and OAB questionnaire (OAB-q) and odds ratio (OR) to measure adverse events rates. We used the Cochrane Collaboration's Review Manager 5.1 software for statistical analysis. RESULTS: We identified six publications that strictly met our eligibility criteria. Meta-analysis of extractable data showed that mirabegron was more effective than placebo in treating OAB despite different drug dosages in the efficacy end points: mean number of incontinence episodes per 24 h (MD -0.54; 95% CI -0.63, -0.45; p = 0.001), mean number of micturitions per 24 h (MD -0.55; 95% CI -0.63, -0.47; p = 0.001), OAB-q (MD -4.49; 95% CI -6.27, -2.71; p = 0.001) and adverse events (OR 0.99; 95% CI 0.83, 1.19; p = 0.92). When compared to tolterodine, mirabegron was more effective in terms of mean number of incontinence episodes per 24 h (MD -0.25; 95% CI -0.43, -0.06; p = 0.009). However, there were no differences between mirabegron and tolterodine in mean number of micturitions per 24 h (MD -0.17; 95% CI -0.35, 0.01; p = 0.07) and OAB-q (MD -1.09; 95% CI -2.51, 0.33; p = 0.13). Mirabegron also had a lower adverse reaction rate (OR 0.9; 95% CI 0.8, 1.0; p = 0.04). CONCLUSIONS: In this diverse population, mirabegron was an effective and safe pharmacologic therapy for OAB.